Field of the Invention
This invention relates to photocurable plastisol and organosol coating compositions. More particularly, it relates to fusible photopolymerizable plastisol and organosols which are photoimagable resists and solder masks.
The plastisol and organosol compositions that are described herein have several advantages over other photoresist and solder mask coating compositions. Both the organosols and the plastisols avoid the problems such as non-uniform mixing and inaccurate metering that is found with two part liquid systems. Further advantages to the present system are contact imagability, aqueous alkali developability, good resolution, and the ability to be used with a variety of application techniques including screen printing.
In addition to these advantages, the present compositions have advantages over known plastisol-organosol compositions. Specifically, known plastisol-organosols disadvantageously, do not have adequate shelf lives, and in fact plastisol-organosol systems of industry, characteristically, suffer from short shelf lives. The plastisol-organosol compositions described herein, however, have a shelf stability that provides remarkably long shelf lives. These long shelf lives are a very needed advantage for the commercial marketing of the photoimagable resist and solder mask plastisol coating composition.